1. Field of the Invention
The present invention relates to a wireless sensor network system. More particularly, the present invention relates to a method and apparatus for allocating a radio resource in a wireless sensor network.
2. Description of Related Art
Wireless sensor networks refer to wireless mesh networks including several tens through several thousands of sensor nodes which may be referred to as sensors. In wireless sensor networks, nodes may communicate with each other using radio frequencies (RFs) to sense physical or environmental conditions.
Also, in wireless sensor network systems, since energy efficiency of sensors is critical, two methods have been proposed in a conventional art to improve the energy efficiency.
First, as an example of the conventional art, sleep cycles of an individual sensor are controlled in a distributed way or centrally controlled by coordinators. Accordingly, when necessary, selected sensors are controlled at selected times to wake up from a sleep state.
Second, as another example of the conventional art, a scheme using data reduction exists. In such a scheme, representative nodes for transmitting data are selected and data is collected.
However, the conventional art described above has the following disadvantages.
According to the first example of the conventional art, network throughput and data transmission delay may not be considered, since the goal is for support to match sleep cycles of a source node and a destination node. Specifically, although energy efficiencies may be improved, network throughput and data transmission delay may not be improved.
According to the second example of the conventional art, an assumption that all sensors included in a particular zone accurately sense a same event at the same time is required. Accordingly, when sensing data information of each sensor is not identical, or collecting all data generated in a particular zone is unnecessary, an application may be meaningless.
Also, according to the first example and the second example, lifetimes of the networks may not be extended.
Accordingly, there is a need for an improved method and apparatus for allocating a radio resource in a wireless sensor network.